Conventional diaphragm walls are known in which concrete is cast directly into a trench formed in the soil and after a cage of metal bars has been put into place.
Since the beginning of the 1970s, as an alternative solution to diaphragm walls, prefabricated walls have been used in which reinforced concrete elements, prefabricated either on site or in a workshop, are lowered into an excavated trench, which is then filled with a slurry of cement-bentonite for sealing the prefabricated elements to the ground in place.
The prefabricated wall technique is preferred in particular when the wall is incorporated in the final work and needs to satisfy aesthetic criteria, or when the thickness of the wall needs to be optimized, or when there are special sealing requirements.
Nevertheless, that technique presents drawbacks associated with the prefabricated elements that are used. Those elements require prefabrication workshops to be built or to exist close to the site. Furthermore, transporting the elements from the fabrication workshop to the site is lengthy and expensive because of their great weight.